23. Some types of ferns resemble trees and others are too(-so) small that they look like moss.

24. Made of sealskin stretched over a framework of whalebone or driftwood, Eskimo completely enclose its kayak (-an Eskimo kayak is completely enclosed) except for the opening in which the paddler sits.

25. Our urge to classify different life forms and giving(-give them) names seems to be as old as the human race.